SCIENTIFIC HIGHLIGHTS RL3, Articles

Improved resistive switching memory devices

A non-volatile memory element in which data is stored in a single high resistance state is built based on back-to-back series connection of two ferroelectric tunnel devices.
Resistive switching elements are attracting a lot of interest, because these are building blocks for artificial intelligence computing. In resistive switching devices a switch from a high resistance to a low resistance and vice versa is produced depending on the prepoling applied voltage. Intermediate resistance states can be also set while sweeping prepoling applied voltage. Ferroelectric tunnel junctions are resistive switching devices, where resistance is modulated by ferroelectric polarization. Ferroelectric tunnel junctions are interesting because they can show improved power consumption, retention and reliability. In a resistive switching memory device, arrays of resistive switching elements are fabricated. However, these arrays present the sneak current problem. The sneak problem results from the fact that reading currents addressed to a high resistance state leak through memory elements in the low resistance state. If the resistive switching memory device is fabricated based on a ferroelectric material the same problem holds. In the highlighted work, it is shown that two different logic states can be stored in a series back-to-back connection of ferroelectric tunnel junctions performing the same high resistance. The two logic states correspond to up-down or down-up polarization state of the two ferroelectric junctions. Therefore, as all the junctions are in high resistance state, the sneak currents are avoided and the device scale-up is possible. Moreover, authors demonstrate that the engineered device shows less power consumption than resistive switching elements based on single ferroelectric tunnel junction.

Complementary resistive switching using metal-ferroelectric-metal tunnel junctions
Mengdi Qian, Ignasi Fina, Milena C. Sulzbach, Florencio Sánchez, Josep Fontcuberta
Small 15, 1805042, 2019
DOI: 10.1002/smll.201805042

Figure: Intensity-Voltage (I-V) characteristics of back-to-back series connection of ferroelectric resistive switching device. Top-left: sketch of the used back-to-back series connection. The device resistance at remanence is always high, but the two ferroelectric devices connected show different polarization up-down or down-up states corresponding to different logic states.

Coordination
Anna May-Masnou This email address is being protected from spambots. You need JavaScript enabled to view it.
Redaction
Anna May-Masnou This email address is being protected from spambots. You need JavaScript enabled to view it.
Web & Graphic Editor
José Antonio Gómez  This email address is being protected from spambots. You need JavaScript enabled to view it.

Webmasters
José Antonio Gómez This email address is being protected from spambots. You need JavaScript enabled to view it.
Albert Moreno     This email address is being protected from spambots. You need JavaScript enabled to view it.
ICMAB